/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.facebook.presto.sql.tree;

import java.util.List;
import java.util.Objects;
import java.util.Optional;

import static java.util.Objects.requireNonNull;

public class GraphPattern
        extends Node
{
    Optional<Identifier> token;
    AnonymousPattern pattern;

    public GraphPattern(Optional<Identifier> token, AnonymousPattern pattern)
    {
        this(Optional.empty(), token, pattern);
    }

    public GraphPattern(NodeLocation location, Optional<Identifier> token, AnonymousPattern pattern)
    {
        this(Optional.of(location), token, pattern);
    }

    public GraphPattern(Optional<NodeLocation> location, Optional<Identifier> token, AnonymousPattern pattern)
    {
        super(location);
        this.token = token;
        this.pattern = requireNonNull(pattern, "anonymousPattern is null");
    }

    @Override
    protected <R, C> R accept(AstVisitor<R, C> visitor, C context)
    {
        return visitor.visitGraphPattern(this, context);
    }

    @Override
    public List<? extends Node> getChildren()
    {
        return null;
    }

    public List<String> getNodeTypes()
    {
        return pattern.getNodeTypes();
    }

    public List<String> getRelationshipTypes()
    {
        return pattern.getRelationshipTypes();
    }

    public List<String> getNodeNames()
    {
        return pattern.getNodeNames();
    }

    public List<String> getRelationshipNames()
    {
        return pattern.getRelationshipNames();
    }

    @Override
    public int hashCode()
    {
        return 0;
    }

    @Override
    public boolean equals(Object obj)
    {
        if (this == obj) {
            return true;
        }
        if ((obj == null) || (getClass() != obj.getClass())) {
            return false;
        }
        GraphPattern o = (GraphPattern) obj;
        return Objects.equals(token, o.token) &&
                Objects.equals(pattern, o.pattern);
    }

    @Override
    public String toString()
    {
        return token.map(identifier -> identifier.getValue() + "=" + pattern.toString()).orElseGet(pattern::toString);
    }
}
